1. Field of the Invention
This invention relates to circuits for the operation of stroboscopic or flashing lights, such as those used in warning light systems, photography, and the like, and in particular to a diagnostic system incorporated into the stroboscopic light circuit for indicating failure of any portion of the circuit.
2. Description of the Prior Art
Flashing lights known as stroboscopic or "strobe" lights are used in a variety of applications, principally as visual warning lights, such as atop moving vehicles, as illuminating devices in photography, and as measuring and testing devices such as in machine revolution counting. The typical stroboscopic light circuit comprises a flash lamp and a source of high-voltage electricity to operate the flash lamp, with a trigger impulse being provided to trigger the illumination of the flash lamp.
The circuit typically comprises a series of component parts. The first portion of the circuit is the electrical voltage supply source. The second portion of the circuit is a fuse connected to the voltage supply source. The third portion is an electrical high-voltage transient filter connected to the voltage supply source to provide a filtered power supply. The fourth portion is a high-voltage power supply. The fifth portion is the flash lamp itself.
Stroboscopic light circuits, as with all devices, are subject to failure. A failure can occur in any of the portions of the circuit previously described, and the location of the failure could only be determined by substitution of the individual portions of the circuit, or through the use of various diagnostic instruments which are costly and which require operation by a skilled technician. These problems were particularly acute in stroboscopic light circuits used to operate visual warning devices, such as those installed as flashing light signals on moving vehicles or atop high towers. In these instances, the light system usually had to be removed from service and taken to a repair area. This practice was time-consuming and sometimes left the installation location without the benefit of a warning light system. To avoid the problem of not having a warning light at the installation location while the repair was taking place, a replacement light system could be temporarily installed. However, this practice was even more expensive because it required replacing the light system twice.
Devices to test the operation of flashing light circuits have been disclosed in U.S. Pat. Nos. 2,901,692, issued to Polhemus, and 3,701,942, issued to Kobayashi et al. In the patent to Kobayashi et al., the entire flash circuit was tested by connecting a test circuit to the flash circuit. The test circuit included an indicating lamp and a test switch, so that when the test switch was closed, the indicating lamp indicated the operation of the flash circuit. However, the device of Kobayashi et al. failed to provide an indication of the location of any failure in the circuit, so that it would not be possible to determine where in the circuit the failure had occurred and to take the appropriate corrective action to repair the circuit and return it to operation.
Various other diagnostic indication systems have been proposed, such as those disclosed in U.S. Pat. Nos. 2,382,647, issued to McLoughlin et al., 3,686,531, issued to Decker et al., 3,840,801, issued to Kellogg et al., and 4,282,479, issued to Deboo et al. However, none of these patents indicate how a diagnostic system may be incorporated into a stroboscopic light circuit to provide the necessary diagnostics to immediately indicate the source of any failure in the circuit.